Groundhogs, also known as woodchucks, are common in areas through the United States and are widely considered pests due to their tendency to damage gardens and lawns. They eat a variety of plants, and, as the University of Maryland Extension points out, they particularly like tomatoes (Solanum lycopersicum). Keeping groundhogs out of your garden can be a challenge, but a variety of non-lethal strategies can be effective.
Members of the rodent family, which also includes squirrels and gophers, groundhogs are brown and have stout, chunky bodies with relatively short legs for their size. They typically measure 16 to 27 inches in length, including the tail, and may weigh 5 to 10 or more pounds. Groundhogs sometimes inhabit suburban areas but are most common in rural regions, where they commonly dig burrows near croplands or other food sources.
If you have groundhogs on your property, you may see them scurry into their burrows as you approach. They are active during the day, spending nighttime underground. In a garden, groundhogs are often responsible for bites taken from tomato fruits and vegetable plants. Occasionally, they make take entire tomato fruits, but often they leave partially chewed portions of fruits still attached to the plants.
One way to reduce groundhog damage is to make your property less suitable for them. Groundhogs usually dig their burrows in protected areas, and you can discourage them from setting up a residence by eliminating brush piles, mowing ditches and embankments, sealing foundations and eliminating open spaces under porches and outbuildings.
These actions make it more difficult -- though not impossible -- for groundhogs to find a suitable burrow location, and also make an established burrow more vulnerable to groundhogs' natural predators, such as foxes.
Resorting to Scaring Them
The effectiveness of scare devices on groundhogs is open to debate. Banging pie plates, noise emitters and shiny reflectors seem to have little effect on groundhogs, according to a University of New Hampshire Cooperative Extension article. That article adds, however: "Scarecrows reportedly can offer temporary relief if they are moved regularly and you incorporate a high level of human activity in the area."
In general, scare tactics need to be moved or changed frequently to have any effect because groundhogs eventually become accustomed to them and are no longer threatened by them enough to pass up the free food offered by a healthy garden.
Fencing Them Out
Fences are the most effective groundhog deterrents, but it is simple to underestimate groundhogs' ability to circumvent poorly made fences. Effectively keep groundhogs at bay by using 1-inch mesh or wire for your fence, and ensure the fence stands at least 3 feet tall above ground. Groundhogs are skilled diggers, and so the fence must also extend 10 to 12 inches below the soil surface. An electric fence is also an option. Place an electrified wire 4 to 6 inches above the ground, and put a second electrified wire 6 to 8 inches above that first wire.
Trapping groundhogs is illegal in some locations and is otherwise inadvisable for a few reasons. By trapping a groundhog in a typical metal trap, you risk exposing yourself to rabies, which can be fatal. Trapping groundhogs is also not as humane as may be assumed, and the animals can become injured.
The question of what to do with the animals once they are trapped is also an issue. In most areas, it is illegal to release groundhogs on state land or another person's property without permission. In Maryland, for example, the law requires that trapped groundhogs be given to animal control to be "humanely destroyed," as the University of Maryland Extension puts it.
Despite being pests, groundhogs are a natural part of the ecosystem. So using control methods that are not harmful to the animals is the best practice.